Machine for mechanically working materials



T" L I I tff m 22,452,211 Vi/j SUBSTITUTE FOR MISSING x Oct. 26, 1948.A. H. ROSENTHAL 2,452,211

MACHINE FOR MECHANICALLY WORKING MATERIALS Filed Oct. 17, '1944 |1 r r72 T 8 5 64 66 65 A 4 IN V EN TOR.

ADOLPH H. FQOSENTHAL BY %Mz4w,

ATTORNEY I EiRCH RQQM.

Patented Oct. 26, 1948 MACHINE FOR MECHANICALLY WORKING MATERIALS AdolphH. Rosenthal, New York, N. Y., assignor to Scophony Corporation ofAmerica, New York, N. Y., a corporation of Delaware Application October17, 1944, Serial No. 559,079

3 Claims. 1

terial is to be removed from the work and while the latter is beingengaged by the tool.

It is therefore an object of the invention to remove material from awork by causing the tool to vibrate mechanically at high, supersonicirequency in a direction essentially parallel to the path in whichmaterial is to be removed.

It is another object of the invention to remove material from a workalong a predetermined path or face by an electrically excited andadjustable vibratory action at high, supersonic frequency of the toolupon the work along that path or face.

It is another object of the invention to remove material from a workalong a predetermined line or face by the electrically excited vibratoryaction at supersonic, high frequency of a tool fed along that line orface in one or more reciprocating feed strokes.

It is still another object of the invention to increase the accuracy andefficiency of removing material from a work, and thereby shaping thelatter by means of a boring, sawing, lapping, etc. tool.

These and other objects of the invention will be more clearly understoodas the specification proceeds-with reference to the drawings in whichFig. 1 shows rather schematically a vertical cross section with parts inelevation of a machine for boring a hole through a work piece, Fig. 2 insimilar way' the working parts of a machine for lapping a hole alreadydrilled through a work piece, and Fig. '3 operative elements of asawing, milling, planing or grinding machine.

Reierrihg to the exemplification of the invention shown in Fig. 1, aframe l0 including a base II is provided with a chuck or mountingfixture of any suitable type for holding the work or blank l2. Forsimplicity's sake, this fixture is shown to consist of a recess It inthe base to receive work l2 in which a bore i3 is to be drilled: work isclamped therein in fixed position by one or more set screws l5.

A feed screw and spindle I8 is journalled on both ends in split bearingsl6, H, the caps 2|, 22

2 of which are held in position by bolts 23, 24. On the end of spindlel8 projecting beyond bearing 16, a hand wheel 25 is mounted, whereas onits other end 20 projecting through bearing ll, a collar 21 is fixed bypin 28.

A toolsupport 26 includes a bushing 29 screw threaded on the inside andengaging feed screw I8. Bushing 29 contacts and glides on Ways 30 spacedfrom feed screw l8 and arranged parallel to its axis on opposite sidesso that upon turning feed screw H3 in one or the other direction bymeans of hand wheel 25, the supportis moved upor downwardly along thoseways for feeding the tool toward the work or withdrawing the tooltherefrom.

A rod 3| is mounted in support 26 by means of its screw threaded end,and is provided on its opposite end with a head 32 in which a tool 33can be removably mounted, for instance clamped by means of screw 34.

Rod 3| consists of ferromagnetic material of I the type which under theinfluence of a magnetic flux passed therethrough longitudinally exhibitsmagneto-striction effects. If the magnetic flux varies periodically inits intensity, this magnetostriction causes longitudinal dilations andcontractions of the rod in the frequency of the recurrent variations inintensity of the magnetic flux acting upon the rod, and results inmechanical vibrations of the rod in its longitudinal direction, 1. e.parallel to its axis. Ferromagnetic materials exhibiting this propertyare for instance nickel or nickel alloys, such as known under the tradenames Invar and Monel metal."

In order to excite rod 3| to mechanical vibrations of this type, coil 35is positioned at a proper place around the rod and fed throughconductors 36 with an exciting alternating electric current of thefrequency at which mechanical vibrations of maximum amplitude can beproduced in rod 3|, i. e. the resonance frequency of the rod.Oscillating currents of this type can be produced by well knowngenerators, for instance a tube oscillator circuit, such as a Hartleycircuit. By tuning the tube oscillator, the frequency of the oscillatingcurrent produced can be adjusted in wide range. Its amplitude can becontrolled by varying for instance the grid bias of a generator oramplifier tube in the oscillatory circuit and thereby the energysupplied to coil 35 and the intensity of the mechanical vibrations ofrod 3| adjusted.

If rod 3| is thus excited to mechanical vibrations in its longitudinaldirection, an oscillation node develops at the place where the rod ismounted in support 26, whereas its freely projecting end connected withhead 32 vibrates mechanically at maximum amplitude in the direction ofdouble arrow 31 if the dimensions of the rod of given composition arechosen so that its length between its ends corresponds to substantiallyA. etc. wave lengths. The frequencies at which such maximum amplitudesof vibrations are obtained are the fundamental resonance frequency ofthe rod or vibratory magneto-striction element and its higher harmonics.They are chosen according to the invention within high, supersonicfrequency range and amount to between about 30,000 to 1,000,000vibration cycles per second.

The mechanical vibrations occurring at the free end of rod 3| aretranslated to head 32 rigidly connected therewith and by the latter upontool 33. The masses of head 32 and tool 33 thus mechanically coupledwith rod 3| will naturally codetermine the resonance frequency of thewhole oscillating unit of which they form a part, and it is easy toadjust the frequency of the exciting oscillatory current supplied tocoil 36 to proper resonance with this mechanical unit.

After the work or blank l2 has been positioned and clamped into themounting fixture, the exciting current is applied to coil 35, andsupport 26 and thereby tool 33 are lowered upon it by turning hand wheel25. Thereby vehement mechanical vibrations of the working tip of tool 33are produced in the direction of double arrow 38 and as soon as the tooltip contacts work l2, a hole is started therein by the mechanicalhitting and carving action of the tool tip at the high, supersonicfrequency stated hereinbefore. Support 26 and thereby tool 33 are feddownwardly by continued rotation of feed screw l8 until the tool tip hascompleted hole l3 through work i2. Thereafter the tool is withdrawn fromthe'work by rotating spindle i8 in the opposite direction and theexciting current is shut oif.

It will be appreciated from the above that in this manner a bore isproduced by means of a tool operated in the longitudinal direction ofthe bore only, without turning the tool. In order to remove thedust-like material carved out by the intense rapidity of work results.The power of each impact depends on the energy by which the mechanicalvibrations of rod 3| are produced, which in turn depends on theintensity of the magnetic fluxes passed therethrough. By adjusting theenergy of the exciting oscillatory current therefore also the intensityof each impact of the tool edge or tip upon the work at each hit can bead- .lusted.

It is within the scope of the invention to interpose an electricallyexcitable vibrator between the mounting fixture for the work and base llinstead of between the tool holder and its support, to the effectshereinbefore described, and particularly if a work of small mass, forinstance a small die or diamond is to be bored.

It is understood by anybody skilled in the art that instead of a manualfeed an automatic one can be provided by which the tool is fed towardand through the work at predetermined speeds and withdrawn after thebore is completed. Work l2 can be either bored through entirely or onlyto predetermined depth. Instead of feeding the tool holder by itssupport toward and from the a vibrator utilising piezo-electric efiectscan be used for producing the vibratory movement of the tool atsupersonic high frequency of the order stated hereinbefore. This isillustrated in Fig. 2 which exemplifies the utilisation of the inventionfor lapping a hole in a wire drawing die produced previously in anymanner. Dies for drawing very fine wires, such as of tungsten andmolybdenum or their alloys, are usually made of cemented carbide ofextreme hardness or include a commercial diamond in which a fine hole isbored and are to be lapped thereafter in order to obtain greatestsmoothness of the hole. Furthermore, when costly dies of this type areworn out in operation, they are usually lapped in order to restoreuniformity and smoothness of the hole;

' thereby the hole is slightly enlarged and the die hitting action ofthe tool point at supersonic fre- .quency, a stream of a liquid orgaseous coolant can be directed upon the upper surface of work I 2 froma nozzle 40.

It should be understood that the dimensions of head 32 and tool 33 inpractice will be made as small as possible in longitudinal direction andthose shown in the drawing are rather exaggerated for claritys sake.Tool 33 can consist of any suitable material, such as hardened steel ora composition known under the trade name Stellite," for instance on acobalt-chromium-tungsten base to which sometimes molybdenum and otheralloying metals are added. The tool can also be provided in specialcases with a working tip of particularly hard and tough material, suchas cemented carbide or a diamond. The tip can be conical and pointed orwedge-shaped, depending on the shape of the bore [3 to be produced. Thetip can be smooth or finely saw-toothed.

The vibrational displacement caused by magneto-striction effects is verysmall, of the order of a few thousandths of an inch, so that the tooltip or edge removes minute amounts of material only at each hit orimpact; these hits follow one another, however, extremely rapidly at thehigh supersonic frequency stated hereinbefore whereirom the surprisingefiect of the invention and thereafter used in a draw for producing asomewhat larger diameter than previously obtained by the same die.

Reverting to Fig. 2, a die 4! is clamped in a chuck or other fixture Mof base II by means of set screw IS in a manner similar to that shown inFig. 1. Tool support 26 otherwise the same as in Fig. l, is providedwith a hole 42 in which a vibratory unit utilizing piezo-electriceffects is mounted.

It consists of a shell 43 tightly fitted into hole 42 and abuttingagainst a shoulder 44. Shell 43 is provided at its lower end with aninwardly projecting rim 45 and screw threaded on the outside, and a cap46 is screwed thereon. Annular washers 41, 48 are positioned between theoutside of rim 45 and the inside of the rimof cap 46, and hold,liquid-tightly clamped between them, an annular sheet-like diaphragm 49,preferably of flexible and springy metal, such as beryllium bronze, orsteel. A bushing 50 screwthreaded on its inside is liquid-tightlymounted within, a center hole of diaphragm 49 and a screw-threadedspindle 5| passed therethrough and liquid-tightly held in adjustedposition by nut 52 and preferably resilient washer 53, e. g. a lockwasher. 6n the inner end of spindle 5| and immersed in the liquid 13 acircular metallic disk 54-is mounted, while the outer end of spindle 5!is provided with a head 55 in which a lapping tool 56 is removablymounted, for instance clamped by set screw 51. An annular ring 58 ismounted in a recess of shell 43, for instance by tight or shrunk fit. isscrew-threaded on its inside and serves as a support for a vibratoryelement operating on the piezo-electric principle. 1

This element consists in this exemplification of two circular steelplates 59, 60 between which a number of pieces 6! of piezo-electricmaterial is mounted, for instance cemented on their top and bottom tothe steel plates 59, 60.

It is well known in the art that crystals of certain substances, such asquartz, tourmaline, Rochelle salt exhibit piezo-electric effects, 1. e.vibrate mechanically under the action of oscillating electrical energyapplied to them in distant planes perpendicular to a polar axis of therespective crystal. The polar axes of such crystals can be ascertainedby well known methods, ,and a plate of rectangular or square crosssection cut from thecrystal in such a manner that two distant parallelsurfaces of the plate are perpendicular to the selected polar axis(Curie out). If oscillating electric potentials are applied to the cutpiece on those parallel surfaces and the frequency of these oscillationsequals substantially the resonance frequency of the cut piece, vehementvibrations of the latter in that resonance frequency are produced. Thevibrations consist in recurrent contractions and expansions of the piecein a direction perpendicular to these surfaces, so that the distancebetween the latter is recurrently reduced and increased; such vibrationsare known as thickness vibrations of the piece. Instead of thesethickness or longitudinal vibrations of the kind just described,transverse vibrations parallel to the planes can be produced and may beutilized; in the latter case, the length of the piece between the planeswill periodically increase and decrease. However, for all practicalpurposes thickness vibrations are preferred.

The resonance frequency of a piece depends upon the crystal materialfrom which it is cut and its dimensions; if other members of a differentmaterial are rigidly connected with the piece or several pieces to forma unitary element, the resonance frequency depends on the thicknesses,masses and sound velocities of the members. Since the sound velocity ofsteel is practically the same as that of quartz, a rigid combination ofquartz elements and steel members oscillates-.as,..., if

one unit with a resonance frequency determined by the total thicknessand shape of the'c'dmbined element.

The resonance curve of the oscillations of any such vibrator isextremely sharp, and it is therefore necessary that the frequency of theapplied exciting electric vibrations equals or almost equals thatresonance frequency, or. that it is a harmonic, preferably odd harmonicthereof.

The energy of the mechanical vibrations thus excited depends on theenergy of the applied electric oscillations and can therefore beregulated within wide range in an exclusively electric manner.

The pieces 6| are cut from such piezo-electric crystal material,preferably quartz, in such a manner that their surfaces contacting steelplates 59, are parallel and perpendicular to a polar axis in thedirection of which the cut piece is capable of thickness vibrations.

The vibrator unit just described is mounted in a metallic cap 62 screwedinto ring 58. A reupon disk 54.

silient washer 53 of electrically conductive material, such as softcopper, is clamped between the inwardly projectin rim of ring 58 and thelower end of cap 62, so that the vibrator element is firmly held withincap 62 between washer 63 and a plate-like insulation 64, for instance ofmica, fibre or the like, on top.

A screw-threaded terminal rod 65 is connected with steel plate 59 andpassed through-a hole in insulation 84 and another insulation 66, forinstance of insulating plastic or ceramic material, so that plate 59 andterminal 65 are completely insulated from cap 62. Another terminal 61 ismounted on support 26 and electrically connected with plate 60 throughthe metallic support, shell 43, ring 58 and washer 63. A conductor 68 isclamped on'to terminal 65 and another conductor 69 (which may begrounded at 10) is clamped anto terminal 61. Any suitable source of highfrequency current H is connected between conductors 68, 69 and can beswitched in and out by means of switch 12. The space within shell 43 isfilled with a suitable sound propagating liquid 13, such as oil.

The total thickness of the vibratory unit 59, *60, 6| is chosen so thatits resonance frequency at which it mechanically vibrates in thedirection of double arrow 14 (thickness-vibrations) is within high,supersonic range between about 30,000 to 1,000,000 vibration cycles persecond. Calculation shows that at a total thickness of 5 mm. or 10 mm.,a resonance frequency of respectively about 600,000 and 300,000vibration cycles per second can be obtained at which, as it is repeated,the entire element contracts and dilates recurrently in the direction ofdouble arrow 14 K at that frequency. In order to excite those resonancefrequencies, the oscillatory currents supplied by source ll must beessen'tially 'of the same frequency because .the resonance frequency ofthe vibratory element forms a sharp curve. However, the excitingfrequency may also be a higher odd harmonic of the fundamental resonancefrequency.

The mechanical vibrations of the lower surface of plate 60 aretranslated upon the contacting liquid 13. Mechanical waves of higsupersonic frequency within the range stated hereinbe'fore progressmainly in a direction perpendicular to the exciting surface, are highlydirected arid do notsubstantially spread laterally. Hence the mechanicalvibrations of the lower surface ofpla'te 60 are translated upon andthrough liquid T3 in a direction essentially perpendicular to thatexposed surface and travel toward the upper surface of the immersed disk54 the area of. which, for the reasons just stated, need not exceedconsiderably the area of the lower surface of plate 60 contacted by theliquid 13 within the circular aperture of ring 58. The distance betweenthe lower surface of plate 60 and the upper surface of disk 54 should bepreferably such, that a standing wave results in the liquid uponreflection of the waves by disk 54.

In this manner and very efficiently, i. e. with least loss of energy,the vibrating energy of the vibrator element is translated throughliquid 13 Thereby disk 54 is caused to vibrate in the direction ofdouble arrow '15 at the same frequency as the vibratory element andtakes with it rod 5!, head 55 and tool 56. These vibrations theexcursions of which are very small, around a few thousandths of an inch,are permitted and followed by the resiliency of diaphra-gm 49.

Since a lapping action is desired, abrasive powder or paste i6 isprovided between the end of tool 56 and the hole I! of the die 4 I.

In operation, support 26 is fedtoward work 4| so far that the end of thelapping tool 56 enters the hole 1! and the abrasive powder therein.after oscillatory currents have been supplied to the vibratory unit fromsource H by closing switch '12. The vibrations of the vibratory unit aretranslated upon tool 56 which therefore vehemently vibrates in thedirection of double arrow 18 and produces the desired lapping action.Whereas tool 33 in Fig. 1 is mounted rigidly in support 26, a kind offloating mount is provided by the embodiment of the invention accordingto Fig. 2 which enhances the desired lapping rather than boring action.While lapping proceeds rapidly. support 26 and thereby tool 56 can befed further toward work 41 and into hole '11. so that lapping canprogress to any desired depth of hole 11. After this operation has beencompleted within a fraction of a minute or a few minutes, the lappingtool is withdrawn by raising support 26 and the oscillatory energy isshut off by opening switch 12.

It should be understood that the two methods described herein withrespect to Figs. 1 and 2 can be combined in that according to the firstmethod the hole is drilled in the drawing die,.and this hole lappedthereafter according to the sec- 0nd method.

It is within the scope of the invention to mount in tool holder 32, Fig.1, or 5!, Fig. 2, any other type of tool than exemplified therein formechanically working a work piece and removing material therefrom. Forthis purpose the boring or lapping tools 33 or 56 shown in Figs. 1, 2are to be replaced by another suitable tool for performing a sawing,milling, filing, grinding or reaming operation. Referrin to Fig. 3 it isassumed that a machine of the type as shown in Fig. l is used. A tool 19is clamped with its shank 82 into tool holder 32. The working face 80 oftool '19 engaging work 8| is saw-toothed, as shown, and tool 19 isblade-like if a sawing operation is intended. If a milling action isintended, the shape and thickness of the teeth of tool 79 correspond tothose of the cutters Of a miller. Similarly, by the use of teeth ofproper width and shape at face 80 of tool 79, a planing operation can beperformed on work 8. If face 80 of tool 19 is shaped like that of afile, a filing action can be obtained, and if face 80 is flat and of acomposition suitable for grinding, e. g. comprisin minute particles ofsilicon carbide embedded in a suitable metallic matrix, a grindingoperation can be performed,

Suitable reinforcements for the back of tool 19, and means for feedingthe work 8| toward the tool in the direction of arrow 84, suchas a feedscrew 83 engaging a chuck or mounting fixture 85 for the work, 01' othermeans well known for cross feeds, can be used- Number In operation, tool19 engagin work BI is mechanically vibrated essentially in the directionof double arrow 86 and simultaneously fed longitudinally e. g. by meansof spindle 18 and hand wheel 25. A cross feed is accomplished in themanner indicated above.

It should be understood that the invention is not limited to theexemplifications hereinbefore described and shown in the drawings, butis to be derived in its broadest aspects from the appended claims. WhatI claim is:

1. In a machine for operating a tool, an enclosure, a body of liquidwithin said enclosure, a member immersed in said liquid, a tool holderoutside said enclosure and connected through a Wall thereof with saidimmersed member, and means for directing supersonic vibratory energythrough said liquid to said member.

21" In a machine for operating a tool, an enclosure having a flexiblewall, a body of liquid within said enclosure, a member immersed in saidliquid, a tool holder outside said enclosure, means connectin saidmember and tool holder and supported by said flexible wall, and meansfor directing supersonic vibratory energy through said liquid to saidmember and tool holder.

3. In a machine for operating a tool, an enclosure with a vibratorydiaphragm formin one wall thereof, a body of liquid within saidenclosure, a member immersed in said liquid, a tool holder outside saidenclosure, means extending through and supported by said diaphragm forconnecting said immersed member and tool holder, and means for directingsupersonic vibratory energy through said liquid to said member and toolholder.

ADOLPH H. ROSENTHAL.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Name Date 1,318,466 Taylor Oct, 14, 1919 1,746,662Legge Feb. 11, 1930 1,966,446 Hayes July 17, 1934 1,990,074 HelmstadterFeb. 5, 1935 2,070,944 Hillix Feb. 16, 1937 2,195,060 Wallace et a1 Mar.26, 1940 2,280,446 Nyman Apr. 21, 1942 2,304,793 Bodine Dec. 15, 19422,350,117 v Kline May 30, 1944 2,354,347 Peets July 25, 1944 2,366,062Sengenberger Dec. 26, 1944 2,384,435 Bodine Sept. 11, 1945 FOREIGNPATENTS Number Country Date 553,176 Great Britain May 11, 1943

